1. Field of the Invention
The present invention relates to the field of electrical connectors, more specifically to an electrical plug-in connector that is plugged in or removed from a socket connector that is connected to a printed circuit board by electrical soldering joints.
2. Description of the Related Art
The electrical plug-in connector providing for the input and output of one or both an electrical power and electrical signals to a separate device has long been well known and which is generally made up of a plug-in connector and a socket connector. This plug-in connector is available in various types, which comprises a plurality of terminal sheaths and the socket connector having a corresponding number of connector terminals which are connected to a printed circuit board by means of soldering and which are, when the plug-in connector is plugged into the socket connector, engaged or plugged into the associated terminal sheaths to establish electric circuits between the connector terminals and the terminal sheaths.
In this particular type of the plug-in connector, it is well understood that whenever the plug-in connector is plugged in or removed from the socket connector compressive or tensile load forces act on the printed circuit board and the electrical soldering joints. Where the socket connector is fixed in position with the connector terminals electrically connected directly with the printed circuit board through electrical joints formed by, for example, soldering, repeated application of compressive and tensile load forces to the printed circuit board will eventually result in degradation of the reliability of the printed circuit board and the electrical soldering joints. It is a general practice to mount the plug-in connector and the printed circuit board separately on a housing of an electrical control device in order to secure a highly reliable electrical control device. In this type of structure, the tensile load forces would be generated when the plug-in connector is removed from the socket connector will not be transmitted to the printed circuit board. However, the difference between the coefficient of thermal expansion of a material for the connector terminals in the socket connector and that of a material for the circuit board is apt to allow thermal stresses to develop at the solder joints. When this happens, damage is likely to result in at least one or possibly all of the solder joints.
The other known solution is to rigidly mount a supporting member against the back side of a socket connector to oppose the alternating plugging forces mentioned above. This rigidly mounted method and apparatus is difficult and costly to implement due to manufacturing tolerances, such as mechanical tolerance, connector soldering placement, etc.
In view of the major drawbacks of the above plug-in type connectors, the inventor have made diligent studies and effort to provide a unique, simple, inexpensive and proven effective method and self-compensating structure for mitigating compressive and tensile stresses and strains on a plug-in connector during alternating plugging and removing of the plug-in connector from a socket connector.